The cables for one offshore wind farm, called Hornsea Three, come ashore at Weybourne and will then be buried in a trench 55 kilometres long to Swardeston.

A second trench, 60km long needs to be dug from Happisburgh to Necton.

Building the cable corridors for the offshore wind farms will take at least six years of construction work and will mean thousands of HGV trips across Norfolk as huge trenches are dug.

Traffic modelling done for Swedish energy firm Vattenfall, which wants to dig the trench 60km from Happisburgh to Necton, predicts a daily increase in the number of HGV movements at peak times by more than 3,300pc on the worst affected road.

The construction work, starting in around 2021, will see thousands of vehicles flood into the county. On the A148 in North Norfolk, HGVs will be coming down 693 times a day, an increase of 63pc, at the height of construction.

The B1147 Dereham Road by Etling Green will see HGV movements increase by 205pc to 34 a day.

The worst affected road will be the Cromer Road at Ingworth. The cable corridor will run between Blickling Hall and Aylsham and there will be 109 HGV movements a day – an increase of 3,300pc from just three without the project.

The other roads seeing the biggest increase in HGV movements will be Elsing Lane (617pc), the B1159 at Horsford (726pc), the B1145 west of Cawston (525pc) and the North Walsham Road at Edinghtorpe Green (1,317pc).

A traffic report for Orsted, which will dig a trench from Weybourne to Swardeston, did not measure increases in HGVs, but it did say how many maximum HGV movements there would be a day at the peak of construction.

Of the 10 busiest roads for HGVs from the project, eight are B roads.

They include the B1149 Holt Road, with 119 HGV movements a day and the B1345 to the River Bure with 122.

The road with the most HGV movements on it for Orsted’s project will be the B1108 Watton Road, running from Norwich to Watton with 171.

Other affected roads are the B1113 Norwich Road near Swardeston where the substation will be built, and the A1067 at Easton.

The works will likely lead to the partial closure of footpaths including the Peddars Way and Norfolk Coast Path as well as the Marriott’s Way at Reepham.

The companies said they were doing all they could to minimise the impact and these figures are the worst-case scenario.